VAD's are commonly used therapeutic devices and include intravenous (IV) catheters. There are two general classifications of VAD's, peripheral catheters and central venous catheters. To ensure VAD's are used and maintained correctly, standards of practice have been developed, which include a cleaning procedure, commonly referred to as flushing a catheter.
VAD standards of practice usually recommend that flush procedures be performed after catheter placement, before fluid infusion, and before and after drug administration, blood sampling, transfusions and parenteral nutrition. The goal of these flush procedures is to confirm catheter patency, avoid drug incompatibilities, ensure complete drug dose administration, prevent thrombus formation and minimize the risk of blood stream infections. Flush procedures require different types and amounts of flush solutions. The most commonly used flush solutions are saline and/or heparin lock solution. The type of flush solution and amount vary depending on the specific type of catheter. Flush solution volumes between 5 and 10 ml are most common but can range from 1 ml to 20 ml.
For flush procedures, an IV line refers to a system that can include a VAD, a tubing set with clamp and a VAD connector as a termination. Common types of VAD connectors are covered by pierceable septums or pre-slit septums made of rubber or another elastomeric material, which permits insertion of a sharp needle cannula in order to infuse fluids into or to withdraw fluids from the catheter. Upon withdrawal of the needle cannula, the septum seals itself. Ports having pre-slit septums are used with blunt plastic cannula or the frusto-conically shaped tip of a syringe barrel. The syringe tip or the blunt plastic cannula (which is usually attached to a syringe) is gently pushed through the pre-slit septum to establish fluid communication.
IV valves, another type of VAD connector that does not require a needle having a sharp tip, are activated by the frusto-conically shaped tip of a syringe barrel to allow fluid communication between the interior of the syringe and the catheter. These valves may contain features for delivering fluid from a storage compartment in the valve to the catheter, and are referred to in the art as positive displacement valves. Such a valve is taught in U.S. Pat. No. 6,206,861.
Bacteria and other microorganisms may gain entry into a patient's vascular system from access hubs and ports/valves upon connection to the VAD to deliver the fluid or pharmaceutical. Each access hub (or port/valve or connection) is associated with some risk of transmitting a catheter related bloodstream infection (CRBSI), which can be costly and potentially lethal.
Throughout the sequence of procedures associated with the transmission of a microorganism that can cause a CRBSI, there are many risks of contact or contamination. Contamination can occur during drug mixing, attachment of a cannula, and insertion into the access hub. Because the procedure to connect to a VAD is so common and simple, the risk associated with entry into a patient's vascular system has often been overlooked. Presently, the risk to hospitals and patients is a substantial function of the diligence of the clinician performing the connection, and this diligence is largely uncontrollable.
Current “recommended practice” for aseptic IV line maintenance and IV drug delivery practices require adherence to a stepwise process referred to as “SASH.” During the first step of the process, the clinician cleans/disinfects (generally with an alcohol swab) the VAD connector. Second, a syringe containing saline is used to flush the IV line or catheter (Saline flush), and then the VAD connector is disinfected a second time. Third, the fluid or pharmaceutical therapy is administered through the IV line or catheter (Administer therapy), the VAD connector is disinfected a third time, followed by a second Saline flush step. The final step, which is dependent upon the patient's need and institutional policy, is a final disinfection of the VAD connector followed by a Heparin lock step, where a small amount of heparin is injected into the IV line or catheter to prevent the formation of thrombi or blood clots. At the conclusion of this tedious stepwise process, the inlet port of the VAD connector is left exposed to the environment. This “recommended practice” requires disinfecting the VAD connector after each step, and makes IV line maintenance a very burdensome and time consuming process. Because the process is so cumbersome, clinicians very rarely implement this “recommended practice” in its entirety, and, thus, patients are exposed to the risk of contracting CRBSIs. Microorganisms populate exposed connector inlet surfaces, and, when the “recommended practice” is not adhered to, the microorganisms can enter the IV line during flushing. Furthermore, blood reflux into the IV line or catheter can cause clot formation inside the lines, and microorganisms from the connector inlet surfaces can colonize blood clots inside the lines and infect the patients during flushing.
A product currently available that aims to combat the problems associated with contaminated VAD connectors is the SwabCap®. This device disinfects a VAD connectors by covering the connector and protecting it from touch and airborne contamination after the cap has been applied. As the SwabCap® is twisted onto VAD connector, a foam pad inside the cap is compressed, releasing the isopropyl alcohol that bathes and passively disinfects the top and threads of the VAD connector while the cap is in place. Friction between the SwabCap® and VAD connector is essential to ensure proper swabbing and disinfecting as the twisting action helps focus the alcohol on the targeted areas. However, for several reasons, the SwabCap® falls short of accomplishing the desired goal of effectively cleaning and disinfecting the VAD connector. First, the caps do not always engage the threads on the catheter hub, so that friction during swabbing may be inefficient. Additionally, the caps are small, and thus, may result in touch contamination when they are being removed. Despite the fact that the caps are bright orange in color so that compliance can be visually confirmed, because the SwabCap® is a separate entity, only the most diligent clinician will utilize the cap after every step of the flush process. Thus, the cap does not ensure compliance with aseptic technique.
Substantial morbid and mortal risk is, therefore, associated with a number of routine procedures defined primarily by the uncontrollable diligence of the clinician administering the therapy. Unfortunately, the result is that a substantial degree of unnecessary risk and injury, in the form of CRBSIs, to patients occurs. There is a need, therefore, for a flush syringe assembly that promotes compliance with aseptic technique by eliminating the additional swabbing and disinfecting steps.